Since my ideas for these two topics are spread over many different threads, I thought I'd collect them here in a summarized and more cohesive form.

Auxiliary Champions

This possible new category of Champions would offer a more unique and specific type of support which could effect other aspects of the game besides combat.

Rogues - the main ability of Rogues would be to increase the chance of getting better loot (higher rank and rarity) from dungeons and campaign battles.  If extra locked chests & traps were implemented in certain battles or dungeons, the rogue would have a chance to open the chests and disarm the traps.  If hidden treasure caches were made an additional drop in some dungeons, the rogue would increase the chance of getting that drop.  (By additional drop, I mean that it drops along with other normal random drops.  It does not replace them.)

Bards - increase rate of energy renewal.  After obtaining a Bard, you could unlock the ability to upgrade the Tavern with gems.  This could reduce the cost of Upgrading Levels, Ranks, and Skills.

Illusionists - has a chance to cast a spell on himself and one other Champion a day which would allow them to enter another Faction's crypt.  If the Illusionist fails on an attempt, then he or she must rest for one day before attempting the spell again.

Enchanters - increase the chance of getting rare Champion drops from Campaign Battles & increase the success rate of upgrading Artifacts

Alchemists - would improve the chance of getting Greater or Superior Potions.  The Alchemist could give you access to the Laboratory where he or she would have a chance of mixing one Experience Potion per day.  Upgrading the Laboratory with gems could allow you to try to mix more than XP Potion a day.  Though you need an additional Alchemist in order to attempt to mix more than one potion, up to a limit of five.   It's possible that the Alchemist Champion would initially be able to attempt making one Lesser Potion of any affinity a day.  But he would require recipes in order to attempt to make Greater and Superior Potions.  The Greater Potion Recipe could have a chance to drop starting at Stage 8 in the Potion Dungeons.  The Superior Potion Recipe could have a chance to drop starting at Stage 12.  The Recipes would drop in addition to normal random drops.

Sages - Let's say there's an Ancient Library inside the Fire Knight's Castle, full of arcane and mysterious tomes (as the castle originally belonged to Wizard King whom the Fire Knight defeated and from whom he took the castle).  The Sage would give you a chance of finding/obtaining one of these tomes (Skill Books).  The Sage would also give you access to the Bastion Library where he or she could research skill tomes.  Though these would be different than normal skill tomes.  If the research (which takes or week or two or longer, depending on the rarity of the tome and level, rank, and rarity of the Sage) is successful, the player would randomly receive either an Attack, Defense, Support, HP, or Auxiliary skill tome.  These can only be applied to the type of Champion stated.  So they're not as valuable as the tomes which can be used by any Champion.  The Library could be upgraded with gems, requiring more Sages to research multiple books at a time, up to a limit of five.

Combat Mentor/Trainers - would allow you to further decrease the time spent leveling in Sparring Pit by investing more gems (allowing you to upgrade the Sparring Pit one or two more times).

Miners - could give access to a Silver Mine (which can be upgraded with Gems to increase production and capacity.  AND/OR, they could allow you to upgrade the Gem Mine one or two more times.

Smiths - grant access to a Smithy/Workshop.  The Smiths can learn how to forge Artifacts.  The Recipes/Instructions for crafting Artifacts would have a chance to drop in the Arcane Keep.  These would drop in addition to normal random drops.  The ingredients for Artifact crafting would drop in the Golem, Spider, Dragon, & Fire Knight dungeons.  Again, these would drop in addition to normal random drops.  However, the Artifacts the Smith is able to forge are randomly assigned an Affinity (Magic, Spirit, Force, or Void) and only the Champions of those certain Affinities can use them. The Smithy can be upgraded with gems, so that your Smith would eventually be able to forge rank 5 and 6 gear.  At first, he would only be able to forge 1 and 2 star gear.  The rarity you wanted could be selected, but each higher rarity would take longer and have a greater failure rate.  More Smiths could forge more artifacts, up to a limit of five.

Tinkers - grant access to the Tinker Shop where gems can be invested in order to lessen the cost of removing artifacts.  But the process takes time, similar to the Sparring Pit.  Though gems can be invested to reduce the time required and to allow more Tinkers to remove gear from additional Champions, up to a limit of five.

EDIT:  I forgot about this.

Druids -  Wilderness area outside the bastion where the Alchemist can be assigned to gather herbs and other plants for the potions he or she mixes.  However, a Druid/Shaman/Witch Doctor Auxiliary would have a better chance at gathering the rare herbs and plants needed.  The Druid would also be able to lower the failure rate of raising chickens at the Chicken Farm (helping make sure they don't die of disease or malnutrition).  See my Chicken Farming thread for more details.